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Date: Wed, 23 Jun 2004 17:05:33 -0400 From: Chris Nelson Subject: [SDL] [Patch] WiseGroup MP-8800 / MP-8866 (PS2 Joystick) In the current cvs version, SDL doesn't handle these Playstation2 controller => USB adapters correctly, in linux. It will always assume that the maximum number of joysticks (2 in the case of the MP-8866, 4 in the case of the 8800) are plugged in. This is bad not only because it allows SDL to exaggerate the number of logical joysticks, but primarily because the joystick axes are mapped incorrectly, all over the place, such that the devices are effectively unusable unless you have the maximum number of joysticks plugged in. My changes to src/joystick/linux/SDL_sysjoystick.c build on another's previous work (which was a special case for this very joystick, actually), and fix both of these problems, as well as making the current code a little more general, to allow for others to more easily drop in code for quirky joysticks such as these. I've tested this code under 2.6.7 as well as 2.4.24... Both work as advertised (provided you load the JOYDEV linux code as a module, otherwise they won't work at all, new code or old, but that's another issue entirely). Though this sounds horribly formal, you have my permission to distribute all of my work on this issue under the LGPL. So there.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 25 Jul 2004 18:31:50 +0000
parents 355632dca928
children
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<HTML
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>SDL_GetRGBA</TITLE
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>SDL_GetRGBA</H1
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><H2
>Name</H2
>SDL_GetRGBA&nbsp;--&nbsp;Get RGBA values from a pixel in the specified pixel format.</DIV
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><PRE
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>#include "SDL.h"</PRE
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><CODE
><CODE
CLASS="FUNCDEF"
>void <B
CLASS="FSFUNC"
>SDL_GetRGBA</B
></CODE
>(Uint32 pixel, SDL_PixelFormat *fmt, Uint8 *r, Uint8 *g, Uint8 *b, Uint8 *a);</CODE
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><H2
>Description</H2
><P
>Get RGBA component values from a pixel stored in the specified pixel format.</P
><P
>This function uses the entire 8-bit [0..255] range when converting color
components from pixel formats with less than 8-bits per RGB component
(e.g., a completely white pixel in 16-bit RGB565 format would return
[0xff, 0xff, 0xff] not [0xf8, 0xfc, 0xf8]).</P
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>If the surface has no alpha component, the alpha will be returned as 0xff
(100% opaque).</P
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>SDL_GetRGB</A
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>SDL_MapRGB</A
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>SDL_PixelFormat</A
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